This invention relates to dental capsules or cartridges, and more specifically to a dental capsule or cartridge having a discharge nozzle initially sealed by a frangible break away sealing or end closure.
In the field of dentistry, the dispensing of various dental materials, e.g. composite resin, cements, sealants and the like, directly to a tooth surface to effect a tooth restoration has been known for some time. Reference is made to the placement of such materials, e.g. filled composite resin material, directly to the site of the restoration using a syringe technique, as disclosed in U.S. Pat. Nos. 3,518,399; 3,900,954 and 4,198,756. These patents disclose the syringing technique of utilizing a capsule filled with a dental material, e.g. a composite material, from which the material was extruded by the displacement of a piston within the capsule by means of a syringe or syringe gun.
Subsequently, others have adopted the technique of syringing dental materials, such as disclosed in U.S. Pat. Nos. 4,330,280 and 4,384,853. As the syringing technique and the use of capsules for dispensing such dental materials has gained recognition as the preferred method of placing dental materials, others followed with other capsule configurations, as evidenced by U.S. Pat. Nos. 4,391,590; 4,619,613; 4,767,326; 4,963,093; 4,969,816; 5,100,320; 5,322,440 and 5,460,523, to cite a few. While the syringing technique and the use of preloaded capsules of the various known constructions proved satisfactory for the placement of various dental materials, difficulty has been encountered in effectively sealing the discharge end of the nozzle to protect the contents of the capsules from contaminants such as dirt, dust, moisture, light and/or the like.
For example, U.S. Pat. No. 3,518,399 issued to William B. Dragan disclosed an embodiment of a capsule having its discharge nozzle initially sealed during the molding of the capsule. Protecting the contents of the capsule that has its discharge nozzle initially sealed thus required a dentist to sever the sealed end with a cutting tool, e.g. a scissor or knife. However, once the sealed end was severed, it could not be readily resealed, if need be.
The other known dental capsules, as indicated in the exemplary patents cited herein, are formed with a discharge nozzle which is opened at the discharge end, and which open end is subsequently sealed with a relatively small sealing cap to protect the content of the capsule, e.g. as shown in U.S. Pat. Nos. 4,391,590; 4,963,093 and 5,100,320 to cite a few. However, the difficulty and/or disadvantages that are encountered in utilizing these small sealing caps to seal the end of a capsule""s discharge nozzle are that a considerable amount of time and tedious labor is required to place such small sealing caps on the discharge end of the nozzle during the manufacture and filling of such capsule. A further disadvantage that has been noted is that frequently in the shipping and handling of such sealed capsule, there is a likelihood of the sealing cap becoming inadvertently separated from the capsule, thereby exposing the contents to contaminants such as air, dirt, dust, moisture, light and the like.
The inadvertent separation of the sealing cap from the nozzle end of the capsule is further aggravated if the sealing cap is color coded to the material placed within the capsule, and/or if the material within the capsule is light cured as disclosed in U.S. Pat. No. 4,391,590. In such an event, the dentist would be unable to know the color of the material within the capsule and/or the material, if light activated, will become prematurely cured within the capsule.
An object of this invent-on is to provide a dental capsule or cartridge with a discharge nozzle which is sealed by an integrally molded sealing cap which is constructed and arranged to be readily broken away to define the nozzle discharge orifice.
Another object is to provide a dental capsule or cartridge having a discharge nozzle sealed by an integrally formed sealing cap formed with a frangible portion whereby the sealing cap can be readily separated from the nozzle to define a discharge orifice from which the material in the capsule or cartridge may be extruded.
Still another object is to provide a dental capsule or cartridge having a discharge nozzle with art integrally molded sealing cap having a frangible portion to facilitate the removal of the sealing cap to define a discharge orifice and which end cap includes means for resealing the discharge orifice in the event it is desirable to reseal the discharge orifice.
Another object is to provide a dental capsule or cartridge having a discharge nozzle formed with an integrally formed sealing cap defining an end seal for the discharge nozzle and which capsule includes a vent adjacent the other open end of the capsule or cartridge through which the capsule or cartridge is filled with a dental material.
It is an advantage that the dental cartridge is able to be sealed by the insertion of a piston or plug without causing a build up of pressure within the capsule or cartridge.
The foregoing objects and other features and advantages are attained by a capsule or cartridge having a body portion defining a reservoir for containing a predetermined amount of material and having a discharge nozzle connected to one end of the body portion and having the opposite end open, through which the material is placed or loaded into the capsule or cartridge. In accordance with this invention, the end of the discharge nozzle is initially integrally sealed with an attached sealing cap during the molding of the capsule or cartridge. The arrangement is such that the integrally formed sealing cap is provided with a readily frangible portion whereby the sealing cap can be readily separated from the end of the discharge nozzle by breaking the sealing cap at the frangible portion to form the discharge orifice through which the contents of the capsule can be extruded or dispensed.
To facilitate filling of the capsule or cartridge with material during a filling operation, a vent is provided adjacent the open end to evacuate any air being displaced during filling. Subsequent to the filling or loading of the capsule, the open end of the capsule and associated vent are sealed by the displaceable piston when seated in the open end.
To reseal the discharge orifice subsequent to xe2x80x9cbreaking offxe2x80x9d of the integrally formed sealing cap, the sealing cap is provided with either a cavity or a spike by which the sealing cap may be used to reseal the nozzle discharge orifice, if so desired.